US President Donald Trump will seek a “historic increase” in military spending to be funded by cuts elsewhere in government.

Mr Trump wants to boost Pentagon spending by $US54 billion ($A70 billion) in his first budget proposal and slash the same amount from non-defence spending, including a large cut in foreign aid, a White House budget official said on Tuesday.

“This budget will be a public safety and national security budget,” Mr Trump told state governors at the White House.

“It will include an historic increase in defence spending to rebuild the depleted military of the United States of America at a time we most need it.”

The US military is already the world’s most powerful fighting force and the United States spends far more than any other country on defence.

Donald Trump explains the increase

Trump says that when he was in college, everyone said we never lost a war. And now, we don't win anymore. (He was in college during Vietnam) pic.twitter.com/s7ycSr9sGl

— Bradd Jaffy (@BraddJaffy) February 27, 2017

In a speech to conservative activists last Friday, Mr Trump promised “one of the greatest military buildups in American history”.

Two officials familiar with Mr Trump’s proposal said the planned defence spending increase would be financed partly by cuts to the State Department, Environmental Protection Agency and other non-defence programs.

A second official said the State Department’s budget could be cut by as much as 30 per cent, which would force a major restructuring of the department and elimination of programs.

Some defence experts have questioned the need for a large increase in US military spending, which already stands at roughly $US600 billion ($A781 billion) annually. By contrast, the United States spends about $US50 billion ($A65 billion) annually on the State Department and foreign assistance.

Mr Trump also said he would talk about his plans for infrastructure spending in a speech to Congress on Tuesday. “We’re going to start spending on infrastructure big,” he said.

Bush attacks Trump over media ban

In a rare and candid TV appearance on Monday (US time), former President George W Bush has taken a swipe at Mr Trump’s perceived attacks on the freedom of the press and his assertion that some of the media were “enemies of the people”.

In an interview on NBC’s Today show, President Bush said a free press was “indispensable to democracy”, and was necessary to hold those in power to account.

“Power can be very addictive and it can be corrosive, and it’s important for the media to call to account people who abuse their power,” he said.

President Bush said while in office he had worked to convince Russian President Vladimir Putin that he needed an independent media.

“It’s kind of hard to tell others to have an independent, free press when we’re not willing to have one ourselves,” President Bush said.

President Bush appeared to promote his new book, which is a collection of portraits of military veterans he has met.

– with AAP